Tagor Posted October 24, 2016 Share Posted October 24, 2016 Hi all, Long time lurker here, but I have finally decided to register and fire out a few mad questions. I spent many hours skulking about ebuild, and picked up an enormous amount of knowledge, so am grateful to all posters both on here and there for being so generous with their expertise.. . I have just completed a hopefully energy efficient house...a timber framed bungalow with a passive slab, very similar to many of the MBC builds here I have ufh coils in the slab, but delayed buying or connecting any heat source. Hot water heating is via a simple immersion, run on night rate electricity. This suits our usage very well as most of our demand in first thing in the morning. We moved in in July and up to now, have not needed much supplemental heat (we have great solar gain through large south facing windows), and have used a simple plug in 3kW electic heater for a few hours in total in the last few weeks.. The plan was to run the plug in heaters for a winter and then make a call on whether an A2W heat pump would be needed. However, SWMBO is now getting jittery and Is not impressed with the electric heater (she does not like the perceived dry heat, or the ugly heater cluttering up our sleek new gaff) and is pushing to get the A2W pump sooner rather than later… I’d like to A) have a quiet and peaceful life and B) kick the A2W can down the road a bit, as I am broke, so was considering what my options are… While looking at in-line water heaters I came across wonderfull things called pool heaters which seem to do exactly what I want..eg put the 2-3kW into the slab rather than the air. While obviously these will not be as efficient as the A2W, I am thinking the difference might be tolerable, at least in the short term. I would plan to top up heat in the slab with 2-3kW at night for a few hours using the pool heater, at night rates. DHW would remain completely separate, and there would be no buffer tanks or any complications, just a circulating fluid in the slab, with electrical heat added directly as needed. Slab would only be at about 22-24 degrees…. So for fairly minimal outlay I would get the option to top up the slab heat as needed, and also get the water circulating in the slab evening out temperatures in hot weather as a bonus… I know its not optimum in terms of efficiency, but it seems quick, cheap, robust … and even if we do get the heat pump in a few years, this would remain a handy back up … There must be some snag?????? Link to comment Share on other sites More sharing options...
Guest Alphonsox Posted October 24, 2016 Share Posted October 24, 2016 Welcome No snag - This is pretty much what we have decided to do. I'm going to be using a small electrically heated buffer tank as the heat source. The plan is to heat up the slab during the E7 period and let it release energy during the day tpping up if necessary. I've not come across pool heaters so can't directly comment. However as long as you can control the temperature and flow to your required level it should be feasible. Do you have a link to your intended pool heater ? Link to comment Share on other sites More sharing options...
ProDave Posted October 24, 2016 Share Posted October 24, 2016 I thought the pool heaters were A2W heat pumps? the only difference being the pool temperature is lower so they may not heat water very hot? but probably hot enough for wet under floor heating. Welcome to the forum by the way. Link to comment Share on other sites More sharing options...
Tagor Posted October 24, 2016 Author Share Posted October 24, 2016 Hi...haven't give much thought to any specific one. But something like this.... http://www.jacksonsleisure.com/swimming-pools/heating/electric-heaters/elecro-3kw-nano-above-ground-swimming-pool-heater/ presumably only used for small pools Thanks for the reassurance so far....I might have an issue convincing my plumber though! Link to comment Share on other sites More sharing options...
PeterW Posted October 24, 2016 Share Posted October 24, 2016 Welcome ..! if you just want direct heating at 2-3kw you would be better with a Willis Immersion unit and let the pump just circulate through that. You should be able to get one for £35 or so and they are easy to fit. Link to comment Share on other sites More sharing options...
Stones Posted October 24, 2016 Share Posted October 24, 2016 I looked at pool heaters briefly, (A2W heat pumps). The big problem with them (at least the ones I looked at) was the minimum operating temperature of +8C. Not much use in winter! +1 on the Willis jacket. Simple and cheap in capital terms. And welcome... Link to comment Share on other sites More sharing options...
Tagor Posted October 25, 2016 Author Share Posted October 25, 2016 Thanks everyone. I had never heard of a Willis jacket.....it seems to be exactly what I need ... And off the shelf to which is a bonus! Link to comment Share on other sites More sharing options...
Barney12 Posted October 25, 2016 Share Posted October 25, 2016 Can one of the knowledgeab folks on here explain how this would be fitted in a underfloor heating scenario? Link to comment Share on other sites More sharing options...
PeterW Posted October 25, 2016 Share Posted October 25, 2016 Errrr.... Loop the Willis across the supply and return of the manifold. Need a fill loop and an expansion vessel (probably no more than 10 litre). Set the rod stat on the Willis to about 45c. Room thermostat calls for heat, trip a contactor/SSR with the immersion on and the pump on the manifold should easily circulate the heated water. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now